Overview
The Veeder-Root 0794390-420 interstitial sensor is a non-discriminating leak detection device engineered for double-walled steel tanks. The Veeder-Root 0794390-420 detects the presence of liquid between the inner and outer tank walls, triggering an alarm signal to compatible automatic tank gauging (ATG) consoles. This critical secondary containment monitoring tool prevents costly environmental spills and regulatory violations in fuel and petroleum storage applications.
Key Features
- Non-discriminating leak detection: Reliably detects any liquid presence in the interstitial space, regardless of fuel type
- 16-foot cable: Extended reach for flexible installation in tank riser pipes
- Broad tank compatibility: Designed for steel tanks 4 to 12 feet in height with 1.5″ I.D. riser pipe or greater
- Immediate alarm notification: Visual and audible alerts plus optional on-site alarm capability for rapid response
- Two-wire connection: Simplified installation with minimal wiring requirements
- Alarm history logging: Compatible TLS systems record incident timestamps and locations for compliance documentation
Technical Specifications
| Part Number | 0794390-420 |
| Manufacturer | Veeder-Root |
| Sensor Type | Non-Discriminating Interstitial Sensor |
| Tank Type | Double-Walled Steel |
| Tank Height Range | 4 ft. to 12 ft. (1.2 m to 3.7 m) |
| Cable Length | 16 feet |
| Required Riser Pipe I.D. | 1.5″ or greater |
| Connection Type | 2-Wire |
| Fuel Compatibility | Gasoline, diesel, kerosene, jet fuel, aviation gas, waste oil, motor oil, and ethanol/biodiesel blends |
| Detection Method | Float-based liquid detection in interstitial space |
Typical Applications
- Petroleum and fuel storage facilities with secondary containment requirements
- Gas stations and convenience store fuel storage
- Industrial and commercial heating oil storage
- Aviation fueling depots
- Environmental compliance and spill prevention systems
- Facilities subject to EPA and state underground storage tank (UST) regulations
Compatibility & Replacements
Compatible With
- Veeder-Root TLS-450, TLS-450PLUS, TLS-4xx (8601 series) automatic tank gauge consoles
- Veeder-Root TLS-350, TLS-350R, TLS-350J, TLS-350PLUS monitoring systems
- Veeder-Root ILS-350, TLS-300i, TLS-300C tank monitoring consoles
- Veeder-Root TLS-250i and ILS-250 systems (with on-site alarm capability)
- Universal Sensor Input/Output modules (USIOM-AC, USM series)
- Double-walled steel tanks with 1.5″ I.D. or larger sensor riser pipe
Replaces / Drop-In Replacement For
This sensor is a standard interstitial monitoring unit for steel tank double-wall systems. Verify compatibility with your specific ATG console model and tank configuration before ordering. Related Veeder-Root interstitial sensors for different tank types include the 0794390-409 (fiberglass tanks) and position-sensitive variants for specialized containment areas. Consult Veeder-Root technical documentation or your system integrator for confirmed cross-references.
Works With
- Veeder-Root TLS (Tank Level Sensor) console software and firmware 4.A or higher
- Veeder-Root ILS (Integrated Leak Sensor) monitoring systems
- Interstitial Sensor Interface Modules (0329358-001 and compatible variants)
- Alarm History Report and Sensor Status Report logging
- Data interface and remote monitoring capabilities on select console models
- On-site visual and audible alarm outputs via TLS console relay control
